Starting Pitcher SwStk% Decliners – Through Apr 23, 2023

Yesterday, I identified and discussed the starting pitchers with at least 20 IP this season and last who have raised their SwStk% marks most. Today, let’s now look at the decliners, the pitchers who have suffered the largest SwSk% declines. We’re still in small sample size territory, but such significant declines are still worrisome, especially if paired with a velocity drop.

Dustin May underwent TJ surgery in mid-2021, ending his season early, and cutting into his 2022. He did return last year to record 30 innings, and while his velocity was down slightly from his 2021 before the surgery, his SwStk% was strong in double digits. This year, both his SwStk% and strikeout rate have plummeted. His four-seam fastball velocity is down again, but every other pitch has been fine, which is odd to see. Incredibly, none of his pitches has generated a double digit SwStk%. It’s been blind faith expecting a big strikeout rate breakout for May, who has never been a big strikeout pitcher aside from a tiny 23 inning sample in 2021. Despite boasting an upper 90s fastball, he’s one of a number of names whose velocity just hasn’t translated. This year, his whiff ability has taken a further hit, though you may not have noticed thanks to his .195 BABIP and 3.3% HR/FB rate. I don’t know what’s going on here, but I would be curious what he might fetch in return if I dangled him to a pitching-starved team.

Wow, Bailey Falter, where’d all the swings and misses go?! His strikeout rate has tumbled down to just 13.6%, which is not what was expected from a guy who struck out 28.8% of batters at Triple-A last year. His four-seam velocity is down a bit, as is his curveball, though his changeup and curveball are actually up. His pitch mix has changed pretty dramatically, as he’s throwing his four-seamer more at the expense of his sinker and slider, while he has upped the usage of his curveball and changeup. It’s strange to see him throw his curveball so frequently, as it has been extremely weak at generating whiffs, sporting a microscopic 3.2% SwStk%. If that doesn’t improve in a hurry, he’s going to need to reduce its usage or stop throwing it altogether. That pitch, along with a drop in his four-seamer SwStk%, explain the overall dip. I don’t think the upside is there to be worth holding onto in shallower leagues for now.

Wow, it definitely surprises me to see Jordan Montgomery’s name third on this list, as his velocities are at career bests across the board! In fact, his four-seam velocity has now increased for five straight seasons, while his sinker remained flat from 2020 to 2021, but aside from that pause, has also risen each season since 2018. That’s pretty amazing. So then it begs the question — how come his SwStk% has dipped into single digits for the first time in his career?! The answer is his curveball just hasn’t been what it’s been historically. It has generated just a 10% SwStk%, versus an 18.3% career average. So that pitch is the key to get his strikeout rate back to where we expected it. And if it does, perhaps the added velocity will help and we’ll see the benefits in his strikeout rate. As an owner, I’m holding here and hoping for the best.

What on Earth has happened to Corbin Burnes?! Am I reading that correctly, his strikeout rate is down to just 19.5%, while his SwStk%, having never finished below 14.5% in a season, is just 11%?! That’s crazy! Since 2021, this is the lowest five-game strikeout rate he’s ever posted. His previous low was 20.7% late last season. All of his velocities are down a bit, but not enough to really ring the alarm bells. He has thrown his changeup a bit more often at the expense of his four-seamer, which would typically result in more whiffs and strikeouts, not fewer. Aside from his cutter, which has generated a slightly lower SwStk%, all of his other pitches are down significantly on their SwStk% marks. In fact, none of his pitches exceed 12.9%, which is shocking considering three of his pitches sport a career mark of at least 18.5%! You gotta have faith that this is just a small sample blip if you’re an owner, but I can’t see I wouldn’t be a little concerned.

Tylor Megill enjoyed a nice velocity bump last year, but he hasn’t been able to hold onto those gains, as he’s reverted right back to where he sat in 2021. Of course, even at the reduced velocity (which is still above average), he was able to post a 12.1% SwStk% and 26.1% strikeout rate, so we can’t really blame it all on the velocity loss. His four-seamer’s SwStk% is down significantly from where it stood the last two seasons, while his changeup’s SwStk% has been cut in half compared with 2021. He went from featuring a pretty strong three pitch mix from a whiff perspective in 2021 to being below average in that department across the board. Combine that with a massive decline in strike percentage, driving a spike in walk rate, and I don’t want him anywhere near my teams.

Wow, a 6% SwStk% is pretty difficult to achieve, but alas, Jordan Lyles has done so. His four-seam velocity sits at a career low, well actually, the lowest since his 2011 debut. He has also become an extreme fly ball pitcher, which is interesting considering he actually used to be a ground ball pitcher, then became league average, then a slight fly ball pitcher. He’s now apparently fully transitioned to an opposite batted ball type distribution, which should be great for his BABIP, but could result in severe gopheritis, especially given the low strikeout rate. I trust you don’t own him on any of your teams and don’t intend to change that!